1 |
#ifndef lint |
2 |
static const char RCSid[] = "$Id: source.c,v 2.35 2003/07/27 22:12:03 schorsch Exp $"; |
3 |
#endif |
4 |
/* |
5 |
* source.c - routines dealing with illumination sources. |
6 |
* |
7 |
* External symbols declared in source.h |
8 |
*/ |
9 |
|
10 |
#include "copyright.h" |
11 |
|
12 |
#include "ray.h" |
13 |
|
14 |
#include "otypes.h" |
15 |
|
16 |
#include "source.h" |
17 |
|
18 |
#include "random.h" |
19 |
|
20 |
extern double ssampdist; /* scatter sampling distance */ |
21 |
|
22 |
#ifndef MAXSSAMP |
23 |
#define MAXSSAMP 16 /* maximum samples per ray */ |
24 |
#endif |
25 |
|
26 |
/* |
27 |
* Structures used by direct() |
28 |
*/ |
29 |
|
30 |
typedef struct { |
31 |
int sno; /* source number */ |
32 |
FVECT dir; /* source direction */ |
33 |
COLOR coef; /* material coefficient */ |
34 |
COLOR val; /* contribution */ |
35 |
} CONTRIB; /* direct contribution */ |
36 |
|
37 |
typedef struct { |
38 |
int sndx; /* source index (to CONTRIB array) */ |
39 |
float brt; /* brightness (for comparison) */ |
40 |
} CNTPTR; /* contribution pointer */ |
41 |
|
42 |
static CONTRIB *srccnt; /* source contributions in direct() */ |
43 |
static CNTPTR *cntord; /* source ordering in direct() */ |
44 |
static int maxcntr = 0; /* size of contribution arrays */ |
45 |
|
46 |
|
47 |
void |
48 |
marksources() /* find and mark source objects */ |
49 |
{ |
50 |
int foundsource = 0; |
51 |
int i; |
52 |
register OBJREC *o, *m; |
53 |
register int ns; |
54 |
/* initialize dispatch table */ |
55 |
initstypes(); |
56 |
/* find direct sources */ |
57 |
for (i = 0; i < nsceneobjs; i++) { |
58 |
|
59 |
o = objptr(i); |
60 |
|
61 |
if (!issurface(o->otype) || o->omod == OVOID) |
62 |
continue; |
63 |
/* find material */ |
64 |
m = objptr(o->omod); |
65 |
while (!ismaterial(m->otype)) |
66 |
if (ismixture(m->otype) || m->omod == OVOID) { |
67 |
m = NULL; |
68 |
break; |
69 |
} else |
70 |
m = objptr(m->omod); |
71 |
if (m == NULL || !islight(m->otype)) |
72 |
continue; /* not source modifier */ |
73 |
|
74 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
75 |
m->otype == MAT_SPOT ? 7 : 3)) |
76 |
objerror(m, USER, "bad # arguments"); |
77 |
|
78 |
if (m->otype == MAT_GLOW && |
79 |
o->otype != OBJ_SOURCE && |
80 |
m->oargs.farg[3] <= FTINY) |
81 |
continue; /* don't bother */ |
82 |
if (m->oargs.farg[0] <= FTINY && m->oargs.farg[1] <= FTINY && |
83 |
m->oargs.farg[2] <= FTINY) |
84 |
continue; /* don't bother */ |
85 |
|
86 |
if (sfun[o->otype].of == NULL || |
87 |
sfun[o->otype].of->setsrc == NULL) |
88 |
objerror(o, USER, "illegal material"); |
89 |
|
90 |
if ((ns = newsource()) < 0) |
91 |
goto memerr; |
92 |
|
93 |
setsource(&source[ns], o); |
94 |
|
95 |
if (m->otype == MAT_GLOW) { |
96 |
source[ns].sflags |= SPROX; |
97 |
source[ns].sl.prox = m->oargs.farg[3]; |
98 |
if (source[ns].sflags & SDISTANT) |
99 |
source[ns].sflags |= SSKIP; |
100 |
} else if (m->otype == MAT_SPOT) { |
101 |
source[ns].sflags |= SSPOT; |
102 |
if ((source[ns].sl.s = makespot(m)) == NULL) |
103 |
goto memerr; |
104 |
if (source[ns].sflags & SFLAT && |
105 |
!checkspot(source[ns].sl.s,source[ns].snorm)) { |
106 |
objerror(o, WARNING, |
107 |
"invalid spotlight direction"); |
108 |
source[ns].sflags |= SSKIP; |
109 |
} |
110 |
} |
111 |
if (!(source[ns].sflags & SSKIP)) |
112 |
foundsource++; |
113 |
} |
114 |
if (!foundsource) { |
115 |
error(WARNING, "no light sources found"); |
116 |
return; |
117 |
} |
118 |
markvirtuals(); /* find and add virtual sources */ |
119 |
/* allocate our contribution arrays */ |
120 |
maxcntr = nsources + MAXSPART; /* start with this many */ |
121 |
srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB)); |
122 |
cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR)); |
123 |
if ((srccnt == NULL) | (cntord == NULL)) |
124 |
goto memerr; |
125 |
return; |
126 |
memerr: |
127 |
error(SYSTEM, "out of memory in marksources"); |
128 |
} |
129 |
|
130 |
|
131 |
void |
132 |
freesources() /* free all source structures */ |
133 |
{ |
134 |
if (nsources > 0) { |
135 |
free((void *)source); |
136 |
source = NULL; |
137 |
nsources = 0; |
138 |
} |
139 |
if (maxcntr <= 0) |
140 |
return; |
141 |
free((void *)srccnt); |
142 |
srccnt = NULL; |
143 |
free((void *)cntord); |
144 |
cntord = NULL; |
145 |
maxcntr = 0; |
146 |
} |
147 |
|
148 |
|
149 |
int |
150 |
srcray(sr, r, si) /* send a ray to a source, return domega */ |
151 |
register RAY *sr; /* returned source ray */ |
152 |
RAY *r; /* ray which hit object */ |
153 |
SRCINDEX *si; /* source sample index */ |
154 |
{ |
155 |
double d; /* distance to source */ |
156 |
register SRCREC *srcp; |
157 |
|
158 |
rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
159 |
|
160 |
while ((d = nextssamp(sr, si)) != 0.0) { |
161 |
sr->rsrc = si->sn; /* remember source */ |
162 |
srcp = source + si->sn; |
163 |
if (srcp->sflags & SDISTANT) { |
164 |
if (srcp->sflags & SSPOT && spotout(sr, srcp->sl.s)) |
165 |
continue; |
166 |
return(1); /* sample OK */ |
167 |
} |
168 |
/* local source */ |
169 |
/* check proximity */ |
170 |
if (srcp->sflags & SPROX && d > srcp->sl.prox) |
171 |
continue; |
172 |
/* check angle */ |
173 |
if (srcp->sflags & SSPOT) { |
174 |
if (spotout(sr, srcp->sl.s)) |
175 |
continue; |
176 |
/* adjust solid angle */ |
177 |
si->dom *= d*d; |
178 |
d += srcp->sl.s->flen; |
179 |
si->dom /= d*d; |
180 |
} |
181 |
return(1); /* sample OK */ |
182 |
} |
183 |
return(0); /* no more samples */ |
184 |
} |
185 |
|
186 |
|
187 |
void |
188 |
srcvalue(r) /* punch ray to source and compute value */ |
189 |
register RAY *r; |
190 |
{ |
191 |
register SRCREC *sp; |
192 |
|
193 |
sp = &source[r->rsrc]; |
194 |
if (sp->sflags & SVIRTUAL) { /* virtual source */ |
195 |
/* check intersection */ |
196 |
if (!(*ofun[sp->so->otype].funp)(sp->so, r)) |
197 |
return; |
198 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
199 |
goto nomat; |
200 |
rayparticipate(r); |
201 |
return; |
202 |
} |
203 |
/* compute intersection */ |
204 |
if (sp->sflags & SDISTANT ? sourcehit(r) : |
205 |
(*ofun[sp->so->otype].funp)(sp->so, r)) { |
206 |
if (sp->sa.success >= 0) |
207 |
sp->sa.success++; |
208 |
if (!rayshade(r, r->ro->omod)) /* compute contribution */ |
209 |
goto nomat; |
210 |
rayparticipate(r); |
211 |
return; |
212 |
} |
213 |
/* we missed our mark! */ |
214 |
if (sp->sa.success < 0) |
215 |
return; /* bitched already */ |
216 |
sp->sa.success -= AIMREQT; |
217 |
if (sp->sa.success >= 0) |
218 |
return; /* leniency */ |
219 |
sprintf(errmsg, "aiming failure for light source \"%s\"", |
220 |
sp->so->oname); |
221 |
error(WARNING, errmsg); /* issue warning */ |
222 |
return; |
223 |
nomat: |
224 |
objerror(r->ro, USER, "material not found"); |
225 |
} |
226 |
|
227 |
|
228 |
int |
229 |
sourcehit(r) /* check to see if ray hit distant source */ |
230 |
register RAY *r; |
231 |
{ |
232 |
int first, last; |
233 |
register int i; |
234 |
|
235 |
if (r->rsrc >= 0) { /* check only one if aimed */ |
236 |
first = last = r->rsrc; |
237 |
} else { /* otherwise check all */ |
238 |
first = 0; last = nsources-1; |
239 |
} |
240 |
for (i = first; i <= last; i++) |
241 |
if ((source[i].sflags & (SDISTANT|SVIRTUAL)) == SDISTANT) |
242 |
/* |
243 |
* Check to see if ray is within |
244 |
* solid angle of source. |
245 |
*/ |
246 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
247 |
<= source[i].ss2) { |
248 |
r->ro = source[i].so; |
249 |
if (!(source[i].sflags & SSKIP)) |
250 |
break; |
251 |
} |
252 |
|
253 |
if (r->ro != NULL) { |
254 |
r->robj = objndx(r->ro); |
255 |
for (i = 0; i < 3; i++) |
256 |
r->ron[i] = -r->rdir[i]; |
257 |
r->rod = 1.0; |
258 |
r->pert[0] = r->pert[1] = r->pert[2] = 0.0; |
259 |
r->uv[0] = r->uv[1] = 0.0; |
260 |
r->rox = NULL; |
261 |
return(1); |
262 |
} |
263 |
return(0); |
264 |
} |
265 |
|
266 |
|
267 |
static int |
268 |
cntcmp(sc1, sc2) /* contribution compare (descending) */ |
269 |
register CNTPTR *sc1, *sc2; |
270 |
{ |
271 |
if (sc1->brt > sc2->brt) |
272 |
return(-1); |
273 |
if (sc1->brt < sc2->brt) |
274 |
return(1); |
275 |
return(0); |
276 |
} |
277 |
|
278 |
|
279 |
void |
280 |
direct(r, f, p) /* add direct component */ |
281 |
RAY *r; /* ray that hit surface */ |
282 |
void (*f)(); /* direct component coefficient function */ |
283 |
char *p; /* data for f */ |
284 |
{ |
285 |
extern void (*trace)(); |
286 |
register int sn; |
287 |
register CONTRIB *scp; |
288 |
SRCINDEX si; |
289 |
int nshadcheck, ncnts; |
290 |
int nhits; |
291 |
double prob, ourthresh, hwt; |
292 |
RAY sr; |
293 |
/* NOTE: srccnt and cntord global so no recursion */ |
294 |
if (nsources <= 0) |
295 |
return; /* no sources?! */ |
296 |
/* potential contributions */ |
297 |
initsrcindex(&si); |
298 |
for (sn = 0; srcray(&sr, r, &si); sn++) { |
299 |
if (sn >= maxcntr) { |
300 |
maxcntr = sn + MAXSPART; |
301 |
srccnt = (CONTRIB *)realloc((void *)srccnt, |
302 |
maxcntr*sizeof(CONTRIB)); |
303 |
cntord = (CNTPTR *)realloc((void *)cntord, |
304 |
maxcntr*sizeof(CNTPTR)); |
305 |
if ((srccnt == NULL) | (cntord == NULL)) |
306 |
error(SYSTEM, "out of memory in direct"); |
307 |
} |
308 |
cntord[sn].sndx = sn; |
309 |
scp = srccnt + sn; |
310 |
scp->sno = sr.rsrc; |
311 |
/* compute coefficient */ |
312 |
(*f)(scp->coef, p, sr.rdir, si.dom); |
313 |
cntord[sn].brt = bright(scp->coef); |
314 |
if (cntord[sn].brt <= 0.0) |
315 |
continue; |
316 |
VCOPY(scp->dir, sr.rdir); |
317 |
/* compute potential */ |
318 |
sr.revf = srcvalue; |
319 |
rayvalue(&sr); |
320 |
copycolor(scp->val, sr.rcol); |
321 |
multcolor(scp->val, scp->coef); |
322 |
cntord[sn].brt = bright(scp->val); |
323 |
} |
324 |
/* sort contributions */ |
325 |
qsort(cntord, sn, sizeof(CNTPTR), cntcmp); |
326 |
{ /* find last */ |
327 |
register int l, m; |
328 |
|
329 |
ncnts = l = sn; |
330 |
sn = 0; |
331 |
while ((m = (sn + ncnts) >> 1) != l) { |
332 |
if (cntord[m].brt > 0.0) |
333 |
sn = m; |
334 |
else |
335 |
ncnts = m; |
336 |
l = m; |
337 |
} |
338 |
} |
339 |
if (ncnts == 0) |
340 |
return; /* no contributions! */ |
341 |
/* accumulate tail */ |
342 |
for (sn = ncnts-1; sn > 0; sn--) |
343 |
cntord[sn-1].brt += cntord[sn].brt; |
344 |
/* compute number to check */ |
345 |
nshadcheck = pow((double)ncnts, shadcert) + .5; |
346 |
/* modify threshold */ |
347 |
ourthresh = shadthresh / r->rweight; |
348 |
/* test for shadows */ |
349 |
for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts; |
350 |
hwt += (double)source[scp->sno].nhits / |
351 |
(double)source[scp->sno].ntests, |
352 |
sn++) { |
353 |
/* check threshold */ |
354 |
if ((sn+nshadcheck>=ncnts ? cntord[sn].brt : |
355 |
cntord[sn].brt-cntord[sn+nshadcheck].brt) |
356 |
< ourthresh*bright(r->rcol)) |
357 |
break; |
358 |
scp = srccnt + cntord[sn].sndx; |
359 |
/* test for hit */ |
360 |
rayorigin(&sr, r, SHADOW, 1.0); |
361 |
VCOPY(sr.rdir, scp->dir); |
362 |
sr.rsrc = scp->sno; |
363 |
/* keep statistics */ |
364 |
if (source[scp->sno].ntests++ > 0xfffffff0) { |
365 |
source[scp->sno].ntests >>= 1; |
366 |
source[scp->sno].nhits >>= 1; |
367 |
} |
368 |
if (localhit(&sr, &thescene) && |
369 |
( sr.ro != source[scp->sno].so || |
370 |
source[scp->sno].sflags & SFOLLOW )) { |
371 |
/* follow entire path */ |
372 |
raycont(&sr); |
373 |
rayparticipate(&sr); |
374 |
if (trace != NULL) |
375 |
(*trace)(&sr); /* trace execution */ |
376 |
if (bright(sr.rcol) <= FTINY) |
377 |
continue; /* missed! */ |
378 |
copycolor(scp->val, sr.rcol); |
379 |
multcolor(scp->val, scp->coef); |
380 |
} |
381 |
/* add contribution if hit */ |
382 |
addcolor(r->rcol, scp->val); |
383 |
nhits++; |
384 |
source[scp->sno].nhits++; |
385 |
} |
386 |
/* source hit rate */ |
387 |
if (hwt > FTINY) |
388 |
hwt = (double)nhits / hwt; |
389 |
else |
390 |
hwt = 0.5; |
391 |
#ifdef DEBUG |
392 |
sprintf(errmsg, "%d tested, %d untested, %f conditional hit rate\n", |
393 |
sn, ncnts-sn, hwt); |
394 |
eputs(errmsg); |
395 |
#endif |
396 |
/* add in untested sources */ |
397 |
for ( ; sn < ncnts; sn++) { |
398 |
scp = srccnt + cntord[sn].sndx; |
399 |
prob = hwt * (double)source[scp->sno].nhits / |
400 |
(double)source[scp->sno].ntests; |
401 |
if (prob > 1.0) |
402 |
prob = 1.0; |
403 |
scalecolor(scp->val, prob); |
404 |
addcolor(r->rcol, scp->val); |
405 |
} |
406 |
} |
407 |
|
408 |
|
409 |
void |
410 |
srcscatter(r) /* compute source scattering into ray */ |
411 |
register RAY *r; |
412 |
{ |
413 |
int oldsampndx; |
414 |
int nsamps; |
415 |
RAY sr; |
416 |
SRCINDEX si; |
417 |
double t, d; |
418 |
double re, ge, be; |
419 |
COLOR cvext; |
420 |
int i, j; |
421 |
|
422 |
if (r->slights == NULL || r->slights[0] == 0 |
423 |
|| r->gecc >= 1.-FTINY || r->rot >= FHUGE) |
424 |
return; |
425 |
if (ssampdist <= FTINY || (nsamps = r->rot/ssampdist + .5) < 1) |
426 |
nsamps = 1; |
427 |
#if MAXSSAMP |
428 |
else if (nsamps > MAXSSAMP) |
429 |
nsamps = MAXSSAMP; |
430 |
#endif |
431 |
oldsampndx = samplendx; |
432 |
samplendx = random()&0x7fff; /* randomize */ |
433 |
for (i = r->slights[0]; i > 0; i--) { /* for each source */ |
434 |
for (j = 0; j < nsamps; j++) { /* for each sample position */ |
435 |
samplendx++; |
436 |
t = r->rot * (j+frandom())/nsamps; |
437 |
/* extinction */ |
438 |
re = t*colval(r->cext,RED); |
439 |
ge = t*colval(r->cext,GRN); |
440 |
be = t*colval(r->cext,BLU); |
441 |
setcolor(cvext, re > 92. ? 0. : exp(-re), |
442 |
ge > 92. ? 0. : exp(-ge), |
443 |
be > 92. ? 0. : exp(-be)); |
444 |
if (intens(cvext) <= FTINY) |
445 |
break; /* too far away */ |
446 |
sr.rorg[0] = r->rorg[0] + r->rdir[0]*t; |
447 |
sr.rorg[1] = r->rorg[1] + r->rdir[1]*t; |
448 |
sr.rorg[2] = r->rorg[2] + r->rdir[2]*t; |
449 |
sr.rmax = 0.; |
450 |
initsrcindex(&si); /* sample ray to this source */ |
451 |
si.sn = r->slights[i]; |
452 |
nopart(&si, &sr); |
453 |
if (!srcray(&sr, NULL, &si) || |
454 |
sr.rsrc != r->slights[i]) |
455 |
continue; /* no path */ |
456 |
copycolor(sr.cext, r->cext); |
457 |
copycolor(sr.albedo, r->albedo); |
458 |
sr.gecc = r->gecc; |
459 |
sr.slights = r->slights; |
460 |
rayvalue(&sr); /* eval. source ray */ |
461 |
if (bright(sr.rcol) <= FTINY) |
462 |
continue; |
463 |
if (r->gecc <= FTINY) /* compute P(theta) */ |
464 |
d = 1.; |
465 |
else { |
466 |
d = DOT(r->rdir, sr.rdir); |
467 |
d = 1. + r->gecc*r->gecc - 2.*r->gecc*d; |
468 |
d = (1. - r->gecc*r->gecc) / (d*sqrt(d)); |
469 |
} |
470 |
/* other factors */ |
471 |
d *= si.dom * r->rot / (4.*PI*nsamps); |
472 |
multcolor(sr.rcol, r->cext); |
473 |
multcolor(sr.rcol, r->albedo); |
474 |
scalecolor(sr.rcol, d); |
475 |
multcolor(sr.rcol, cvext); |
476 |
addcolor(r->rcol, sr.rcol); /* add it in */ |
477 |
} |
478 |
} |
479 |
samplendx = oldsampndx; |
480 |
} |
481 |
|
482 |
|
483 |
/**************************************************************** |
484 |
* The following macros were separated from the m_light() routine |
485 |
* because they are very nasty and difficult to understand. |
486 |
*/ |
487 |
|
488 |
/* illumblock * |
489 |
* |
490 |
* We cannot allow an illum to pass to another illum, because that |
491 |
* would almost certainly constitute overcounting. |
492 |
* However, we do allow an illum to pass to another illum |
493 |
* that is actually going to relay to a virtual light source. |
494 |
* We also prevent an illum from passing to a glow; this provides a |
495 |
* convenient mechanism for defining detailed light source |
496 |
* geometry behind (or inside) an effective radiator. |
497 |
*/ |
498 |
|
499 |
static int weaksrcmod(obj) int obj; /* efficiency booster function */ |
500 |
{register OBJREC *o = objptr(obj); |
501 |
return((o->otype==MAT_ILLUM)|(o->otype==MAT_GLOW));} |
502 |
|
503 |
#define illumblock(m, r) (!(source[r->rsrc].sflags&SVIRTUAL) && \ |
504 |
r->rod > 0.0 && \ |
505 |
weaksrcmod(source[r->rsrc].so->omod)) |
506 |
|
507 |
/* wrongsource * |
508 |
* |
509 |
* This source is the wrong source (ie. overcounted) if we are |
510 |
* aimed to a different source than the one we hit and the one |
511 |
* we hit is not an illum that should be passed. |
512 |
*/ |
513 |
|
514 |
#define wrongsource(m, r) (r->rsrc>=0 && source[r->rsrc].so!=r->ro && \ |
515 |
(m->otype!=MAT_ILLUM || illumblock(m,r))) |
516 |
|
517 |
/* distglow * |
518 |
* |
519 |
* A distant glow is an object that sometimes acts as a light source, |
520 |
* but is too far away from the test point to be one in this case. |
521 |
* (Glows with negative radii should NEVER participate in illumination.) |
522 |
*/ |
523 |
|
524 |
#define distglow(m, r, d) (m->otype==MAT_GLOW && \ |
525 |
m->oargs.farg[3] >= -FTINY && \ |
526 |
d > m->oargs.farg[3]) |
527 |
|
528 |
/* badcomponent * |
529 |
* |
530 |
* We must avoid counting light sources in the ambient calculation, |
531 |
* since the direct component is handled separately. Therefore, any |
532 |
* ambient ray which hits an active light source must be discarded. |
533 |
* The same is true for stray specular samples, since the specular |
534 |
* contribution from light sources is calculated separately. |
535 |
*/ |
536 |
|
537 |
#define badcomponent(m, r) (r->crtype&(AMBIENT|SPECULAR) && \ |
538 |
!(r->crtype&SHADOW || r->rod < 0.0 || \ |
539 |
/* not 100% correct */ distglow(m, r, r->rot))) |
540 |
|
541 |
/* passillum * |
542 |
* |
543 |
* An illum passes to another material type when we didn't hit it |
544 |
* on purpose (as part of a direct calculation), or it is relaying |
545 |
* a virtual light source. |
546 |
*/ |
547 |
|
548 |
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
549 |
(r->rsrc<0 || source[r->rsrc].so!=r->ro || \ |
550 |
source[r->rsrc].sflags&SVIRTUAL)) |
551 |
|
552 |
/* srcignore * |
553 |
* |
554 |
* The -dv flag is normally on for sources to be visible. |
555 |
*/ |
556 |
|
557 |
#define srcignore(m, r) !(directvis || r->crtype&SHADOW || \ |
558 |
distglow(m, r, raydist(r,PRIMARY))) |
559 |
|
560 |
|
561 |
int |
562 |
m_light(m, r) /* ray hit a light source */ |
563 |
register OBJREC *m; |
564 |
register RAY *r; |
565 |
{ |
566 |
/* check for over-counting */ |
567 |
if (badcomponent(m, r)) |
568 |
return(1); |
569 |
if (wrongsource(m, r)) |
570 |
return(1); |
571 |
/* check for passed illum */ |
572 |
if (passillum(m, r)) { |
573 |
if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID)) |
574 |
return(rayshade(r,lastmod(objndx(m),m->oargs.sarg[0]))); |
575 |
raytrans(r); |
576 |
return(1); |
577 |
} |
578 |
/* otherwise treat as source */ |
579 |
/* check for behind */ |
580 |
if (r->rod < 0.0) |
581 |
return(1); |
582 |
/* check for invisibility */ |
583 |
if (srcignore(m, r)) |
584 |
return(1); |
585 |
/* check for outside spot */ |
586 |
if (m->otype==MAT_SPOT && spotout(r, makespot(m))) |
587 |
return(1); |
588 |
/* get distribution pattern */ |
589 |
raytexture(r, m->omod); |
590 |
/* get source color */ |
591 |
setcolor(r->rcol, m->oargs.farg[0], |
592 |
m->oargs.farg[1], |
593 |
m->oargs.farg[2]); |
594 |
/* modify value */ |
595 |
multcolor(r->rcol, r->pcol); |
596 |
return(1); |
597 |
} |